Interlocking control apparatus



Feb. 2.8, 1939. E. M. ALLEN I INTERLOCKING CONTROL APPARATUS 4 Sheets-Sheet l Filed Dec. 21, 1937 INVENTORy .AllelL HIS ATTORNEY .ESR B Feb. 28, 1939. E. M ALLEN NTERLOCKING CONTROL APPARATUS 193'? 4 Sheets-Sheet 2 Filed Deo. 2l,

E. M. ALLEN INTERLOCKING CONTROL APPARATUS Feb. 28, 1939.

Filed Deo. 2i, 193'? 4 Sheets-Sheet s Feb. 28, 1939. E. MA ALLEN v INTERLOCKING CONTROL APPARATUS Filed Dec. 2l, 1957 4 Sheets-Sheet 4 l HIS ATTORN EY Patented Feb. 28, 1939 UNITED STATES PATENT OFFICE IN TERLOCKING CONTROL APPARATUS Application December 21, 1937, Serial No. 181,007

10 Claims.

My invention relates to interlocking control apparatus for railway track switches and signals in railway switching or interlocking layouts.

One feature of my invention is the provision of novel and improved means, effective after a signal has been cleared, for retaining the signal in the clear condition independently of erroneous attempts to clear an opposing signal or to operate a switch of the interlocking layout. Another feature of my invention is .the provision of novel and improved traffic ydirection control and locking apparatus.

The apparatus of my invention is an improvement over that disclosed in the copending applications Serial No. 323,286, iiled December 3,

1928, by Lester E. Spray for Multiple control apparatus; Serial No. 416,061, led December 23, 1929, by Howard A. Thompson for Multiple control apparatus; Serial No. 561,422, filed September 5, 1931, by Lester E. Spray for Multiple control apparatus; Serial No. 695,294, filed October 26, 1933, by Earl M. Allen and Howard A. Thompson for Interlocking control apparatus; Serial No. 726,957, led May 22, 1934, by Lester E. Spray for Interlocking control apparatus; and Serial No. 19,462, led May 2, 1935, by Paul P. Stoker for Traic controlling apparatus.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying'drawings, Figs. 1A and 1B, when placed end to end, with Fig. 1A on the left, constitute a diagrammatic view showing one interlocking layout of switches and signals in Fig. 1A, and a second interlocking layout of switches and signals in Fig. 1B, with a passenger station shown in Fig. 1A adjacent an intermediate stretch of track between these two interlocking layouts; Figs. 2A and 2B show the home or caution control signal relays, designated by the reference character I-IR with distinguishing numerical prexes, and the circuit network for controlling these relays for the signals shown in Figs. 1A and 1B, respectively; Figs. 3A and 3B show the distant or proceed control signal relays, designated by the reference character DR with distinguishing numerical prefixes, and the circuit network for controlling these relays for the signals shown in Figs. 1A and 1B, respectively;

Figs. 4A and 4B show lever repeater or primary -control relays, designated by the reference character LP with distinguishing numerical prexes, and the circuit network for controlling these relays for the layouts shown in Figs. 1A and 1B,

respectively; traiiic control relays I2FR and I IIFR, together with their control circuits, are also shown in Fig. 4B; Fig. 5 shows approach locking control relays, with typical control circuits shown for relays 2-4MR and IZMR.; Fig. 6 shows switch locking and control relays, designated by the 5 reference characters LS and WR, respectively, with distinguishing numerical prefixes, and shows typical circuits for relays ILS and IWR; Fig. 7 shows polarized lever repeater relays, designated by the reference character LR with distinguishl0 ing numerical prefixes; and Fig. 8 shows route locking relays, designated by the reference characters ES and WS with distinguishing numerical prefixes, and a traffic locking relay I3EWSP.

Similar reference characters refer to similar 15 parts in each of the views.

Referring rst to Figs. 1A and 1B, these drawings show tracks aa and bb of a stretch of double track railway. In the layout shown in Fig. 1A, tracks aa and bb are interconnected through a 20 crossover ee with which they are respectively joined by switches 3 and 3a, and are likewise interconnected by a second crossover ff with which they are respectively joined by switches 5 and 5a. Tracks aa and bb are also respectively 25 joined to passing sidings cc and dd by switches I and I. In the layout shown in Fig. 1B, tracks aa and bb are interconnected through a crossover hh with which they are respectively joined by switches I5 and I5a. Track bb is also joined 30 to passing siding gg by switch I1.

The rails of tracks aa and bb are divided by insulated joints 23 to form a plurality of track sections (iA-IIIA, IIIA-IGA, I (iA-22A, iA-IZA,

I 2A-I4A, and I4A--20A. Each of these track 35 sections is supplied with current by a battery 24 connected across the rails adjacent one end of the section. A track relay, designated by the reference character TR, with a distinguishing numerical prefix, is connected across the rails 40 adjacent the opposite end of each tracksection.

Signals designated by the reference numerals 2, 4,6, 8, I0, I2, I4, I6, I8, 20 and 22 are placed adjacent the ends of these sections. The signals as here shown are of the color light type, signals 45 2, 4, 6, I8, 20 and 22 each having three lamps, a green or proceed lamp G, a yellow or caution lamp Y, and a red or stop lamp R, and signals 8, I0, I2,

I4 and I6 each having only tWo lamps Y and R. Signals 2, 4, 6, I4 and I6 govern traiic movements 50 toward the right, as shown in the drawings, which I shall assume to be the eastbound direction, and signals 8, I D, I2, I 8, 20 and 22 govern trailic movements in the opposite or Westbound direction. 55

Control levers, each designated by the reference character V with a numerical prefix corresponding to the number of the signal or switch controlled by the lever, are shown in Figs. 1A and 1B adjacent the representations oi the signals or switches which the corresponding levers control.

In each of the views, the contacts operated by the various relays or other devices are identified by numbers, each such number having a distinguishing prefix, from which it is separated by a dash, when the contacts are shown apart from the relay or other control devices by which they are operated. The prefix for Yeach of these contact numbers comprises the reference character for the respective relay or other device. Forexample, contact 2ER-29 shown in'Fig. 1A in -the control circuits for signal 2 is identiiied by the number 29 separated by a dash from the prefix EHR which is the reference character for relay ZI-IR by which this contact is operated. Similarly, contact 2li-9.3 shown in the control circuit for relay Z-IILP adjacent this relay in Fig. 4A is identified by the number 93 separated by a dash from' the prefix 2V which is the reference character for lever 2V by which this contact is operated.

Each track switch is operated by a mechanism such, for example, as IW shown for switch I. Each switch mechanism is controlled by a polarized switch control relay. Mechanism IW for switch I, for example, is controlled by relay IWR, the'c'ontrol circuitsl for which are shown in Fig, 6.

Operated in Vconjunction with each switch mechanism is a pole changer, similar to pole changer Iy shown for switch I in Fig. 1A, for controlling a polarized indication relay IKR. With switch I in the normal" position shown in the drawings, current is supplied from a source not shown but having terminals B and O, over the contacts of pole changer Iy vfor energizing relay IKR in the normal direction, whereas, when switch I is operated tothe reverse position, pole changer AIy reverses the polarity of the current which energizes relay IKR. Relays 'IKR and IlKR for switches 'I and I1, respectively, are coritrolled similarly to relay IKR. Only one indication relay BKR is shown for crossover ce, the circuits *for this relay being so arranged in a well-known manner that, when both switches 3 and Scare in the normal position, relay SKR will be energized by current of normal polarity, andwhen both switches 3 and 3a are in the reverse position, relay 3KR will be energized by current of reverse polarity. Relays SKR and IEKR for Crossovers ff and hh, respectively, are controlled similarly to relay 3KR. Y Each of the indication relays, designated by the reference character KR with a distinguishing numerical prefix corresponding to the number of the switch or switches by which it is controlled, controls a normal and a reverse indication relay designated bythe reference characters NP and RP, respectively, with a distinguishing numerical prefix, similarly to the manner in which relays IRP and INP are shown controlled by neutral contact 25 and polar contact 25a of relay IKR in Fig. 1A.

Each of the signals having three lamps is controlled, as shown for signal 2, by its home signal relay HR and by its distant signal relay DIR, each of which has a numerical prex associated with the referencecharacters HR and DR corresponding to the, signal which it controls. Each of the signals which have two lamps is controlled, .as

shown for signal I 6 in Fig. 1B, by only its HR relay.

In Figs. 4A and 4B, circuit networks are shown for controlling lever repeater or primary control relays which are designated by the reference character LP with distinguishing numerical prexes. In the interlocking layout shown in Fig. 1A, parallel traffic movements can be made over two groups of interconnecting routes, that is, a traffic movement can be made in either direction over either of the intersecting routes which include switches 3 and 5 in the normal position and switch l in the normal or reverse position, at the same time that a traic movement can be made in either direction over either of the intersecting routes which includes switches 3a and 5a vin the normal position and switch I in the normal or the reverse position. For each end of each group of intersecting routes which are thus in parallel with one or more other routes, an LP relay is provided,-as shown in Figs. 4A and 4B. The number of LP relays is therefore twice the number of possible contemporaneous parallel movements. Since there are two groups of parallel routes shown in Fig. lA, four LP relays are provided for the interlocking layout shown in Fig. lA. Four LP relays are `also kprovided for the layout shown in Fig. 1B.

. A manual control device, here shown as a lever designated by the reference character V with a distinguishing numerical prex, is provided for each route end. In order'to energize any relay LP, the lever for one of the route ends at the corresponding end of a group of intersecting routes must be reversed, while the lever for the opposite end of the route must be in its normal position. In order to energize relay B-ISLP, for example, for the route extending from Ysignal 8 to signal I5, lever 8V must be reversedfor the corresponding route end, and lever 6V for .the opposite end of the route must be in its 'normal position. If switches 5 and 5a were reversed and switch 3a were in its normal position, levers 2V and 4V for the opposite ends of the two possible routes would have to be in the normal position for relay S-IIJLP to be energized.

As shown in thedrawings, each relay LP is equipped with a make-before-break contact, such, for example, as contact 99 of relay 8-IiJLP in Fig. 4A, which closes at its front pointSQb before opening at its back point 99a. The pick-up circuits for each relay LP include the back point of the make-before-break contact ofthe corresponding relay LP and also of the relay LP for an opposite route end. The stick circuit or circuits for each relay LP include the front point of its own make-before-break contact and a reverse contact for a lever for a corresponding route end, but are independent or" the position of the lever or the relay LP for the opposite endv of the same route.

In Fig. 4B, a trafc direction control arrangement is shown for Yuse with the network circuits of Figs. 4A and 4B for theLP relays. A traffic lever IEV controls trai'c relay IZFR or HIFR for track bb according as lever- ISV is in one position or the other. An asymmetric unit 35 is connected across the winding of each of the traic control relays IZFR and MFR in order to make these relays slightly slow in releasing. The unit 35 may be of the copper oxide rectifier type, with the low resistance direction-indicated by the arrow head portion ofthe symbol for Ydevice 35 shown in the drawings. rTraiiic indication lamps, designatedfby the'reference characters IZFK and NFK', are controlled by traiiic relays I2FR and MFR, respectively. A traffic control arrangement similar to that which is shown for track bb could also be provided for track aa, if desired.

In Fig. 5, circuits are shown for approach locking relays 2 4MR and IZMR, with a release stick relay 2-4-I 2S controlled by a time element ,device '2-4-I2TE which may be of the wellknown clockwork type.

In Fig. 6, a` typical switch lock relay circuit is shown for relay ILS controlled by approach lockingrA relays and by track relays. Normal and reverse control circuits are also shown in Fig. 6 for a switch control relay IWR energized by current from batteries QI and Q2 having a common terminal C.

Fig. '7 shows polarized lever repeater relays LR controlled by the neutral lever repeater or primary control relays LP which are shown in Figs. 4A and 4B. Each polarized relay LR is energized by current of one polarity when the LP relay for one end of a group of intersecting routes is energized while the LP relay for the opposite end of the same group of intersecting routes is deenergized. Each polarized relay LR is energized by current of the opposite polarity when the LP relay yfo-r the first end of the group or' intersecting routes is deenergized while the LP relay for the oppositev end of the same group of intersecting routes is energized.

In Fig. 8, circuits are shown for controlling route locking relays ISES and I3WS, which in turn control a traflic locking relay ISE-WSP. Route locking relays SES and SWS may be con- ;trolled similarly to relays ISES and I3WS, and

may in turn control a traiiic locking relay similarly to the manner in which relays I3ES and I3WS control relay ISE-WSP. As shown in Fig, 4B, trafc direction control is provided for track bb but is not shown for track aa. Contact SES-#|93 of route locking relay SES is therefore inserted inthe HR relay network in Fig. 2B near relay ISI-IR, and contact QWS-ISQ of route locking relay SWS is inserted in the HR relay network in Fig. 2A near relay IGI-IR.

Having described, in general, the arrangement and control of the various parts of one form of apparatus embodying my invention, I shall now describe in detail the operation of the apparatus.

v A s shown. in the drawings, all parts of the apparatus are in normal condition, that is, the Various track sections .are unoccupied, and hence the track relays are energized; the track switches are in the normal position; the signals are indicating stop; the manual control lever for each route end is in the normal position; traffic lever ISV is in the right-hand position; switch levers v IV, 3V, 5V, 7V, I5V and I'IV are in their normal position; the KR relays and the WR relays are energized by current of normal polarity; neutral relays NP, I AFR, MR, LS, ES, WS and |3E-WSP, and traffic direction indicating lamp MFK, are energized; and relays RP, HR, DR, LP, IZFR, 2-4-I 2S and LR, and traiiic direction indicating lamp IZFK, are deenergized.

Of the circuits by which the various parts are energized, the circuits for the red lamps of the signals are similar to that which is shown for signal 2, Fig. 1A, passing from terminal B of a suitable source of current not shown in the drawings, through back point of contact 2ER-29, and lamp' R of signal 2 to terminal O of the same source of current.

The polarized switch indication or KR. relays in Fig. 1A are energized by current of normal polarity supplied by' circuits which are similar to the circuit shown for relay IKR, which includes pole changer Iy operated in conjunction with switch I which is in the normal position. The normal switch indication or NP relays are energized by circuits similar to that shown for relay INP, passing from terminal B, through contact 25 of relay i KR, contact 25a of relay IKR in the left-hand position, and the winding of relay INP to terminal O.

Relay I IIFR in Fig. 4B is shown energized by its pick-up circuit passing from terminal B, through the iront point of contact I3E-WSP--3I, contact ISV- 32 in the right-hand position, contact 33 of relay iZFR, and the winding of relay MFR to terminal O. Traiic direction indicating lamp MHK is energized by a circuit including contact 3B of relay IQFR.

Approach locking relay Z-GMR in Fig. 5 is energized by stick circuits passing from terminal B, through contacts 2HE- 31, 4HR-38, 2-4- I2LR-3S in multiple with contact 2-4-I 2LR 40, front point of contact 4I of relay 2--4MR, and the winding of relay Z-IZMR to terminal O. Approach locking relay I ZMIR, is energized by a stick circuit which is somewhat similar to that just traced for relay 24MR through contact 2 4-I2LR-39. A second stick circuit for relay IZMR is similar to the stick circuit for relay 2-4MR through contact 2-l-I2LR40, but is normally open at contact 2 4-I2LR-4'L The closed stick circuit for relay I2MR passes from terminal B, through contacts I2HR-45, 2 4- IELR-l front point of Contact i8 of relay IZMR, and the winding of relay I2MR to terminal O. The other approach locking or MR relays are energized by stick circuits which are similar to the circuits shown for relays 2-4MR and i 2MB., but which are not shown in the drawings.

Switch locking relay ILS in Fig. 6 is energized by circuits including terminal B, contact 2 4MR-55, Contact (SMR-56 in multiple with contact SNP-57, contact B-IlllWRf-SB in multipley with contact SNP-59, contact IZMR-SG, con-I tact TTR-62 in multiple with a path through*` contact SNP-63 in series with Contact SNP-$13 contact ITB-S5, and the winding of relay ILS to terminal O. Switch locking relays for the other switches, designated by the reference character LS with distinguishing numerical prefixes, are also energized by circuits which are similar to the circuits just traced for relay ILS.

Switch control relay IWR in Fig. 6 is energized by current of normal polarity passing from the battery QI, through contact IV-GB in the left-hand or normal position, Contact 61 of relay ILS, and the winding of relay IWR back to the common terminal C of batteries QI and Q2. The other switch control or WR relays are energized by circuits similar to that just traced for relay WR.

Route locking relay ISES in Fig. 8 is energized by pick-up circuits passing from terminal B, through contact 2-4MR-58, contact SMR- 69 in multiple with contact SNP-lli), contact TTR- 'EI in multiple with contact SNP-l2, contact ITE-J3, and the winding of relay I3ES to terminal O. Stick circuits are also closed for relay ISES, passing from terminal B, through contact 2-4MR-68, contact MR-GS in multiple with contact BNP-l0, contact 'I4 of relay ISES, and the winding of relay I3ES to terminal O. Route locking relay I3WS is energized by a pick-up circuit passing from terminal B, through contacts I8-20MR--16 and I'ITR--11, and the winding of relay IBWS to terminal O. A stick circuit is also closed for relay IjlWS,L which is the same as the pick-up circuit just traced except that it includes contact 'I8 of relay IBWS instead of contact HTR-Ti. Route locking relays SES and SWS are energized by circuits which are similarto the circuits just traced for relays I3ES and I3WS, but which are not shown in the drawings.

Tra-flic locking relay I3E-WSP in Fig. 8 is energized by a circuit passing from terminal B, through contact Sii of relay ISES, contact 8| of relay lSWS, andthe winding of relay ISE-WSP to terminal O'. I shall assume that, with all parts of the apparatus thus in the normal condition the leverman or operator desires to arrange the apparatus for an eastboundtrain to proceed from track dd over track bb. He will therefore move switch lever IV to the reverse position, completing a circuit for energizing relay IWBl in Fig. 6 by current of reverse polarity, this circuit passing from terminal C of batteries QI and Q2, shown in Fig. 6, through the winding of relay IWR, contact rtfi of relay ILS, and contact IV-66, closed in the reverse or right-hand position, backl to battery Q2. With relay IWR energized by current of reverse polarity, a reverse operating circuit will be completed for switch mechanism IW, shown in Fig. 1A, this circuit passing from terminal B, through contact IWB- 26, contact IWR-v28 inthe right-hand position, mechanism IW, contact iWR-Z'I in the right-hand position, and mechanism IW to terminal O.

The operator will then move lever 2V to the reverse position, thereby completing a pick-up circuit for relay Z-tLP, passing from terminal B, through contact 82 of relay MFR, contact i2V-83, contact Bil-84a of relay I2LP, contacts .5V-35, BKR-86, SKR-8l, :iV-88, IKR- 89 closed in the right-hand position, contact IV-Sil closed in the right-hand position, contact 9 I --9Ia of relay E--BLR contact 2V-93, and the winding of relay 2--4LP to terminal O. Relay 2-4LP, upon becoming energized by its pick-up circuit, closes its iront contact 9I--9Ib, and then opens its back contact 9I--9Ia, thereby completing a stick circuit passing from terminal B, through contact lil-9H), contact 2V--93, and the winding of relay 2-1-5LP to terminal O.

With relay 2-211? energized, relay 2 4- IZLR in Fig. 7 will become energized by current of reverse polarity passing from terminal B, through contact 2-4LP-I38 closed at the front point, contact IZLP--illli closed at its back point, winding of relay 2-4--I2LR, contact I2LP--I39 closed at the back point, and contact 2-4LP-I 4I With relay 2-liMR deenergized, contact Z--liMR-EE operated by this relay will be opened in the circuits previously traced for relay ILS in Fig. 6, causing relay ILS to become ,deenergized and in turn open its contact Sl, and thereby dcenergize relay IWR. Switch locking relays ,SLSand 5LS and switch control relays SWR and iii/VR will be similarly deenergized.

With switch I occupying the reverse position, pole cha-nger rly will-be in the reverse position, causing switch `indication relay IKR to be energized by current of reverse polarity With relay-IKR energized by current of reverse polarity, reverse indication relay IRP will be Yenergized by current passing from terminal B, through contact 25 of relay IKR, contact 25a of relay IKR in the right-hand position, and thewinding of relay i RP to terminal O.

With relay Z-AMR deenergized, contact 2-4MR-68 in the circuits previously traced for relay ISES will be opened, causing relay ISES to be deenergized. With relay I3ES deenergized, contact 80 of this relay will open the circuit previously traced for relay I3E-WSP, causing relay lE-WSP to also be deenergized. With relay ISE-WSP deenergized, the pick-up circuit previously traced for relay ILlFR will be opened at the front point of contact I3E-WSP-3I, but relay MFR will now be retained in the energized condition by its stick circuit passing from terminal B, through the back point of contact iSE-WSP-SI, contact 3l! of relay MFR, and the Winding of relay MFR to terminal O.

With the various relays energized or deenergized as described, a circuit will now be complete ior energizing relay 2HR, this circuit passing from terminalB, through contact I2lVl`R-I42, contact 2-4-I ZLR-I 43 closed in the right-hand position, front point of contact 2-4-I2LR-I44, contacts SLS-|45, NP-Ii, SNP-|41, 3LS- M8, lLS-I49, ERP-|50, front point of contact Z-l--IZLR-Il, contact 2--4-I2LR-I52 closed in the reverse position, and the winding of relay ZHR to terminal O.

If signal I is indicating stop, the yellow lamp ofV signal 2 will be lighted by its circuit passing from terminal B, through the front point of contact 2ER-29, back point of contact Z--DR-ll, and lamp Y of signal 2 to terminal O.

If, however, signal I4 has been cleared, by energization of its control relay IliHR similarly to the energization of relay 2HE, and if track section I2A-I4A is unoccupied, distant control relay 2-4DR will be energized by its circuit passing from terminal B, through the front point of contact IiHR-IQf-i, contact MTR-ISS, back point of contact I2HR-l96,'contacts SNP-|91, ETR- m8, SNP-ISS and ZHR-ZML and the winding of relay 2-liDR to terminal O. With relay 2-4DR energized as Well as relay ZHR, green lamp G of signal 2 will be lighted by its circuit passing from terminal B, through the front point or" contact 2ER-29, front point of contact DR-3, and lamp G of signal 2 to terminal O.

I shall assume that, with signal 2 displaying either the caution or the proceed indication, the operator erroneously attempts to clear the opposing signal I2 by moving lever I2V to its reverse position. From Fig. 4A, it will be understood that, since contact SI-Bla of relay 2-4LP is now open, the opening of contact I2V-83 in the pick-up circuit previously traced for relay E-IiLP can have no eiect on relay 2--4LP which will continue energized by its stick circuit previously traced through contact 9I-9Ib.

I shall now assume that, with signal 2 indicating proceed and signal I4 indicating caution, aneastbound train Ypasses signal 2, causing relay ETR to become deenergized. With relay ITR deenergized, its contact ITR-|98 will open the circuit for relay 2--4DR, causing relay 2--4DR to be deenergized and therefore causing signal 2 to return to the caution indication. On account of contacts of relay' ITR being included in the switch locking -relay circuits, such, for

example, as contact ITB- 65 in the circuit previously traced for relay ILS in Fig. 6, the circuits previously described for relays ILS, SLS and 5LS will now be open at these contacts of relay I TR as well as at contacts of relay Z-IIMR,

such, for example, as contact 2--4MR-55 in the circuits for relay ILS, thus preventing energization of relays ILS, BLS and SLS due to energization of relay 2-4MR as long as a train occupies the section extending from signal 2 to signal I2.

When the train enters the section between signals I2 and I4, relay I3TR will become deenergized, thereby opening its contact I3TR-I95 in the circuit for relay 2-4DR and in the circuit for relay I8-20DR which is similar to the circuit previously traced for relay 2-4DR,. Therefore, as long as the section between signals I2 and I4 isoccupied, the operator cannot cause a signal for governing traffic movements into this section such, for example, as signal 20, to display the proceed indication.

The operator can, however, by returning lever 2V to the normal position and thereby consecutively deenergizing relays 2--4LP, 2-4-I2LR and ZHR, cause relay 2-4MR to become energized. If the operator returns lever 2V to the normal position while a train occupies section lTR, relay 2-4MR in Fig. 5 will become energized by a pick-up circuit passing from terminal B, through contacts 2HE-31, 4BR-38, 2 4- I2LR-39, and I'IRf*44, and the winding of relay 2-4MR, to terminal O.

If, however, the operator should fail to return lever 2V to the normal position before the train has left the section between signals 2 and I2, he can cause relay 2-4MR to become energized, upon the lapse of a measured period of time, by setting time element device 2 4-I2TE into operation and thereby completing a circuit for energizing relay 2-4-I2S in Fig. 5, passing from terminal B, through contacts 2HE-31, IHR-38, 2-,4-I2LR 39, back point of contact 4I of relay 2-4MR., contact 2.-4-I2TE-53, and the winding of relay 2-4-I 2S to terminal O. When relay 2-4-I2S becomes energized, it will continue energized by its stick circuit which is the same as the pick-up circuit just traced except including its own contact 54 instead of contact 2-4-I2TE-53 of the time element device. The operator will nowv return the time element device to its normal position, causing its contact 24I2TE42 to complete a pick-up circuit for relay 2-V-4MR through contact 2-4-I 2S-43.

With relay 2-4MR, energized, relay I3ES, when relay I'I'R, is energized, will become energized by its pick-up circuits previously traced,

and with relay I3ES thus energized, relay ISE-WSP will ag'ain become energized by its circuit previously traced. With relay IBE-WSP energized, the operator can, if he sodesires, by reversing lever ISV, complete a circuit for energizing relay I2FR, this circuit passing from terminal B, through the front point of contact I3E-WSP-3I, contact I3V-32 in the left-hand position, contact 33 of relay MFR, and the winding of relay IZFR to terminal O.

The operator can clear signal I2v.by reversing lever I2V while lever 2V is in its normal position. With relay IZFR now energized, the operator can also Yclear signal bylmoving lever ZIIV to .the reverse Vposition while lever I 4V is in the normal position. The circuit forrelay I8-20LP, completed by the operatic-n of lever 20V to its reverse position while relay IZFRisenergiZed, is similar to the circuit previously traced for relay 2-4LP and can, therefore, be readily followed on the drawings without further description.

I shall assume that al1 parts of the apparatus are returned to the normal condition, and that the operator reverses switches 3 and 3a by operation of lever 3V to the reverse position, similarly to the manner in which the operation of switch I to its reverse position is accomplished as previously described. I shall also assume that the operator, in order to clear signal I2, then moves lever I2V to the reverse position, thereby completing a circuit for energizing relay I2LP, this circuit passing from terminal B, through contact (5V-408, contact IElS-Iila of relay GLP, contacts 3V-I I I, SKR- I I2, 5KR86, STI-85, contact i4-84a of relay I2LP, contact INT- 96, and the winding of relay EZLP to terminal O. With relay IZLP thus energized, relay 2-4-52LR in Fig. 7 will become energized by current of normal polarity passing from terminal B, through the bach point of contact 2-4LP-I38, front point of contact HLP-|39, winding of relay 2-4- I2LR, front point of contact IZLP-Hi, and the back point of contact 2-4LP-I4I to terminal O. With relay 2--4--I2LR energized by current of normal polarity, the circuit previously traced for relay I ZMR will be opened at contact 2-4-I2LR-46, causing relay IZMR to become deenergized. Relay IZMR, upon becoming deenergized, opens the circuits previously traced for relay ILS through contact IZMR-, causing relay ILS to become deenergized and to in turn deenergize relay IWR. Relays SLS and ELS will .also be deenergized, similarly to relay ILS, and hence relay IZHR will now be energized by a circuit passing from terminal B, through contacts EMR-Ill, S-8-I9LR-IS9, 3LS-l68, SRP-451, SNP-46, ELS-|45, front point of contact 2-4-I2LR-I44, contact 2-4-I2LR- |43 closed in the normal position, and the winding of relay IZHR to terminal O. The yellow lamp of signal I2 will now be lighted by a circuit including a front contact of relay IZHR.

From the foregoing description and the accompanying drawings, it follows that, in apparatus embodying my invention, one lever repeater or primary control relay is provided for each end of each group of intersecting routes over which a trailic movement can be made at the saine time that a trafc movement is being made over another ro-ute which may be in another group of intersecting routes. A manual control device is provided for each route end. Each primary control relay has a pick-up circuit over its own back contact, for each route with which it is associated, which is controlled by a reverse contact of the manual control device for an associated route end and by a normal contact of the manual control device for the opposite end of the same route, as well as by a back contact of the primary control relay for the opposite end of the same route. Each primary control relay has a stick circuit which is controlled by a reverse contact of the manual control device for an associated route end but which is independent of the position of the manual control device for the opposite end of the route. clear an opposing signal or an attempt to move a switch over which a route is arranged will, therefore, have no effect on a signal which is already cleared. l v

A traiiic direction control and locking scheme is also provided in the accompanying drawings for two adjacent interlocking layouts, such, for

An erroneous attempt to claim is:

In an interlocking control system for a plurality of railway tracks interconnected by switches to form a plurality of routes including a group of intersecting routes and another route in parallel with each of said intersecting routes,

signals for the ends of said routes for governing trafc movements through the routes, a control relay for each end of said group of intersecting routes and for each end of said parallel route ing; cluding a given control relay associated with a plurality of said intersecting routes, a manual control device for each end of each of said routes each having a normal and a reverse position, a pick-up circuit for each oi said control relays for each route with which the control relay is associated and each of said pick-up circuits controlled by the manual control device for the associated end oi the route in the reverse position and by the manual control device for the opposite end of the route in the normal position, a stick circuit for each of said control relays for each route with which the control relay is associated and each stick circuit controlled by the manual control device for the associated end of the route in the reverse position independently of the position of the manual control device for the opposite end of the route, and means controlled by each of said control relays in the energized condition for clearing a signal for a corresponding route.

2. In combination, a stretch of railway track including a plurality of intersecting routes, signals governing traffic movements in opposite directions over said routes, a control relay for each end of said stretch, a manual control device for each route end having a normal and a reverse position, a pick-up circuit for each of said control relays for each route end at the corresponding end loit said stretch and each of said pick-up circuits controlled by the manual control device for the corresponding route end in the reverse position and by the manual control device for the opposite end of the route in the normal position, a stick circuit for each of said control relays for each route end at the corresponding end of said stretch and each of said stick circuits controlled by the manual control device for the corresponding route end in the reverse position independently of the position of the manual control device for the opposite end of the route, and means controlled by said control relays in the energiaed condition for clearing signals for corresponding routes.

3. In combination, a stretch of railway track including a plurality of intersecting routes, signals governing tralic movements in opposite directions over said routes, a control relay for each end of said stretch, a manual control device for each route end, a pick-up circuit for each of said control relays for each route end at the corresponding end of said stretch and each of said pick-up circuits controlled by operation of the manual control device for the corresponding route end and by back contacts of the control relays for both ends of the corresponding route,

a stick circuit for each of said control relays for each route end atfthe corresponding end of said stretch and each of said stick circuits controlledv signals governing traffic movements in opposite directions over said stretch, a control relay for each of said signals, a manual control device for each of said relays each having a normal and a reverse position, a pickup circuit for each of said control relays jointly closed by its manualV control device in the reverse position and by back contacts of the corresponding control relay and of the control relay for the signal at the opposite end of the stretch, a stick circuit for each of said control relays controlled by its manual control device in the reverse position and by a iront contact of the corresponding relay independently of the condition of the control relay for thek opposite end of the corresponding route, and means controlled by each of said control relays in the energized conditionV for clearing the corresponding signal.

5. In combination, a stretch of railway track including a plurality of intersecting routes, signals governing traffic movements in opposite directions over said routes, a control relay for each end of said stretch, a manual control device for each route end having a normal and a reverse position, means controlled by each of said manual control devices for energizing the control relay for the corresponding end of said stretch when said manual control device is in the reverse position and for preventing energization of the control relay for the opposite end of said stretch when said manual control device is moved out of its normal position, a polarized relay, means controlled by said control relays for energizing said polarized relay by current'of normal or reverse polarity according as a first one of said control relays is energized while the second is deenergized or the rst of said control relays is deenergized while the secondV is energized, ya signal relay for each route end, means controlled by said polarized relay for energizing a signal relay for one or the other end of said stretch according as said polarized relay is energized'by current of normal or of reverse polarity, and means controlled by each of said signal relays for clearing a corresponding signal.

6. In combination, a stretch of railway track including a plurality of intersecting routes having a plurality of route ends at one end of said stretch, signals governing traffic movements in opposite directions over said routes, a control relay for each end of said stretch, a manual control device for each route end having a normal and a reverse position, means controlled by each manual control device in its reverse position and by the manual control device for the opposite end of the same route in its normal position for energizing the control relay for the same end of the stretch as the manual control device which is in the reverse position, means controlled by the manual control device for the same end of the stretch in its reverse position for retaining each control -relay in the energized condition independently of the position of the control device for the opposite end oi the same route, and means controlled by said control relays for clearing corresponding signals.

'7. In combination, a stretch of railway track over which traffic movements may be made in either direction comprising an interlocking layout of switches and signals at one end of said stretch and a second interlocking layout of switches and signals at the other end of said stretch as well as an intermediate section of track between said interlocking layouts, an approach locking relay which becomes deenergized when said iirst interlocking layout is arranged for traffic ymovements toward said intermediate section, a second approach locking relay which becomes deenergized when said second interlocking layout is arranged vfor traic movements toward said intermediate section, a route locking relay deenergized upon deenergization of said iirst approach locking relay and retained in the deenergized condition while a train moves through said iirst interlocking layout, a second route locking relay deenergized upon deenergization of said second approach locking relay and retained in the deenergized condition while a train moves through said second interlocking layout, a tralic locking relay controlled by said route locking relays and deenergized when either of said route locking relays is deenergized, a traffic lever having a rst and a second position, a first and a second traffic relay, a pick-up circuit for said first traflc relay closed by said traffic locking relay in the energized condition and by said traiiic lever in its iirst position, a pick-up circuit for said second trafc relay closed by said trac locking relay in the energized condition and by said traiiic lever in its second position, a stick circuit for each of said traflic relays closed by said traffic locking relay in the deenergized condition independently of the position of said traffic lever, and means controlled in part by said first and second traffic relays for arranging said rst or second interlocking layout respectively to direct trafc movements toward said intermediate section.

8. In combination, a stretch of railway track over which trarne movements may be made in either direction, a traic locking relay controlled to be normally energized but to become deenergized when a train approaches said stretch of trackfrom either direction, a trac lever havingwa first and a second position, a first and a second trailc control relay, a pick-up circuit closed by said traflc locking relay in the energized condition and by said trafc lever in its ilrst or second position for energizing said rst or second trac control relay respectively, a stick circuit for each of said traiiic control relays closed by said traiiic locking relay in the deenergized condition for retaining each of said trafc control relays in the energized condition, and means controlled in part by said first or second traic control relays in the energized condition for directing traiiic movements in a first or second direction respectively toward said stretch of track.

9. In combination, a stretch of railway track, a rst signal for a given end of said stretch for governing traiic movements in a given direction over said stretch, a second signal for the opposite end of said stretch for governing trailic movements in the opposite direction over said stretch, a first and a second control relay, manual control means for selectively energizing one or the other of said control relays, a polarized relay, meansv controlled by the first of said control relays in the energized condition and by the second of said control relays in the deenergized condition for energizing said polarized relay by current of normal polarity, means controlled by said first control relay in the deenergized condition and by said second control relay in the energized condition for energizing said polarized relay by current of reverse polarity, and means controlled by said polarized relay only when energized by current of normal or reverse polarity for clearing said first or said second signal respectively.

10. In combination, a stretch of railway track, a polarized relay, manually controllable means for selectively energizing said polarized relay by current of normal or reverse polarity, means controlled by said polarized relay when energized by current of normal or reverse polarity for directing traflic movements in a first direction or in the opposite direction respectively over said stretch, a first and a second approach locking relay, a control circuit for said first approach locking relay controlled in part by a back neutral contact of said polarized relay in multiple with a normal polar contact of the same relay, a control circuit for said second approach locking relay controlled in part by a back neutral contact of said polarized relay in multiple with a reverse polar contact of the same relay, and traffic governing apparatus for said stretch controlled by front contacts of said first and second approach locking relays.

EARL M. ALLEN. 

